1. Technical Field
The present disclosure relates to light emitting diode (LED) lighting devices and, more particularly, to LED lighting devices, which enable the assembly of one or more LED products into a variety of structures for use in a broad range of applications including street lights, security lighting, tunnel lights, floodlights, etc.
2. Background Art
Generally, light emitting diodes (LEDs) are developed based on characteristics of a compound semiconductor emitting light upon application of current thereto, and have a smaller size and longer lifespan than other light sources while exhibiting excellent efficiency in converting electrical energy into light.
Recent advances in semiconductor technology have enabled commercialization of a white LED having high brightness and a variety of lighting devices using the white LED have been introduced.
In particular, various research has been actively conducted into development of an LED lighting module capable of illuminating a sufficiently large area through high-density integration of LED devices in series or parallel to increase the degree of luminous intensity per unit area, namely, brightness, to several thousand cd/cm2 or more.
However, an increase in integrated density of LEDs leads to an increase in the amount of heat generated per unit area, causing damage to the LEDs by heat generated from the LEDs.
An example of LED lighting device includes a metallic heat sink, which exhibits good heat dissipation efficiency and is attached to a lower side of a printed circuit board (PCB), to enhance heat dissipation efficiency.
For example, referring to FIG. 1, an LED lighting device includes a single PCB 100, a plurality of LED devices 110 mounted on the PCB 100, a heat sink 120 attached to a lower side of the PCB 100, and a case 130 covering the LED devices on the PCB 100.
In this LED lighting device, however, heat transfer from the LED devices to the heat sink is obstructed by the flexible PCB and a bonding agent located therebetween and having low thermal conductivity, and only a single heat sink is used for heat dissipation of all the LED devices, causing heat to concentrate at the center of the lighting device. As a result, the LED lighting device cannot effectively dissipate the large amounts of heat generated by high density LED devices, thereby increasing a likelihood of damaging the LED devices during light emission that involves heat generation.
As such, since multiple LED devices are mounted on a single substrate and are operated by DC power in the LED lighting device, the entire lighting device needs to be replaced, even if any one or a few of the LED devices in the lighting device are damaged.
Further, since the LED lighting device has a circuit structure in which the multiple LED devices are supported by a single PCB, the LED lighting device has a limit in realization of various structures and enables structure change only through production of new molds, which is uneconomical.
The foregoing discussion in this section is to provide general background information, and does not constitute an admission of prior art.